diff --git a/src/to-json/Cargo.lock b/src/to-json/Cargo.lock
index 3efbc0d..71b6233 100644
--- a/src/to-json/Cargo.lock
+++ b/src/to-json/Cargo.lock
@@ -2,6 +2,90 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
+[[package]]
+name = "hashbrown"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
+
+[[package]]
+name = "indexmap"
+version = "1.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10a35a97730320ffe8e2d410b5d3b69279b98d2c14bdb8b70ea89ecf7888d41e"
+dependencies = [
+ "autocfg",
+ "hashbrown",
+]
+
+[[package]]
+name = "itoa"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4217ad341ebadf8d8e724e264f13e593e0648f5b3e94b3896a5df283be015ecc"
+
+[[package]]
+name = "ryu"
+version = "1.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4501abdff3ae82a1c1b477a17252eb69cee9e66eb915c1abaa4f44d873df9f09"
+
+[[package]]
+name = "serde"
+version = "1.0.147"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d193d69bae983fc11a79df82342761dfbf28a99fc8d203dca4c3c1b590948965"
+
+[[package]]
+name = "serde_json"
+version = "1.0.87"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ce777b7b150d76b9cf60d28b55f5847135a003f7d7350c6be7a773508ce7d45"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "serde_yaml"
+version = "0.9.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d232d893b10de3eb7258ff01974d6ee20663d8e833263c99409d4b13a0209da"
+dependencies = [
+ "indexmap",
+ "itoa",
+ "ryu",
+ "serde",
+ "unsafe-libyaml",
+]
+
 [[package]]
 name = "to-json"
 version = "0.1.0"
+dependencies = [
+ "serde_json",
+ "serde_yaml",
+ "toml",
+]
+
+[[package]]
+name = "toml"
+version = "0.5.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8d82e1a7758622a465f8cee077614c73484dac5b836c02ff6a40d5d1010324d7"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "unsafe-libyaml"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1e5fa573d8ac5f1a856f8d7be41d390ee973daf97c806b2c1a465e4e1406e68"
diff --git a/src/to-json/Cargo.toml b/src/to-json/Cargo.toml
index a8c79b7..4e6f0af 100644
--- a/src/to-json/Cargo.toml
+++ b/src/to-json/Cargo.toml
@@ -9,3 +9,6 @@ crate-type = ["cdylib"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+serde_json = "1.0.87"
+serde_yaml = "0.9.14"
+toml = "0.5.9"
diff --git a/src/to-json/src/ffi.rs b/src/to-json/src/ffi.rs
index fef3e3a..fc0b297 100644
--- a/src/to-json/src/ffi.rs
+++ b/src/to-json/src/ffi.rs
@@ -1,4 +1,5 @@
 use std::ffi::{c_char, CStr, CString};
+use crate::json::to_json;
 
 #[no_mangle]
 pub unsafe extern "C" fn free_rust_string(string: *const c_char) {
@@ -13,6 +14,7 @@ pub unsafe extern "C" fn to_json_rust(content: *const c_char) -> *const c_char {
     println!("Raw content -> {}", content);
 
     // TODO: convert to JSON format
+    let content: String = to_json(content); // may return empty string
 
     CString::new(content).unwrap().into_raw()
 }
diff --git a/src/to-json/src/json.rs b/src/to-json/src/json.rs
new file mode 100644
index 0000000..83efc4c
--- /dev/null
+++ b/src/to-json/src/json.rs
@@ -0,0 +1,32 @@
+use serde_json as json;
+use serde_yaml as yaml;
+
+enum Format {
+    JSON(json::Value),
+    YAML(yaml::Value),
+    TOML(toml::Value),
+}
+
+fn parser(content: &str) -> Option<Format> {
+    if let Ok(data) = json::from_str::<json::Value>(content) { // try JSON format
+        return Some(Format::JSON(data));
+    }
+    if let Ok(data) = toml::from_str::<toml::Value>(content) { // try TOML format
+        return Some(Format::TOML(data));
+    }
+    if let Ok(data) = yaml::from_str::<yaml::Value>(content) { // try YAML format
+        return Some(Format::YAML(data));
+    }
+    return None; // parse failed
+}
+
+pub fn to_json(content: &str) -> String { // convert to JSON format
+    match parser(content) {
+        Some(data) => match data {
+            Format::JSON(dat) => json::to_string(&dat).unwrap(),
+            Format::YAML(dat) => json::to_string(&dat).unwrap(),
+            Format::TOML(dat) => json::to_string(&dat).unwrap(),
+        },
+        None => String::from(""), // failed -> empty string
+    }
+}
diff --git a/src/to-json/src/lib.rs b/src/to-json/src/lib.rs
index 57ae9b9..4f1b9a0 100644
--- a/src/to-json/src/lib.rs
+++ b/src/to-json/src/lib.rs
@@ -1 +1,2 @@
 mod ffi;
+mod json;